The present invention relates generally to gauges and, more particularly, to gauges having illuminated dials and pointers such as the gauges used in automotive applications for speedometers, fuel gauges and the like.
Gauges with illuminated dials and pointers have been made for many years, for a variety of different applications. One of the largest applications for such gauges is the automotive industry where gauges having illuminated dials and pointers are used in large numbers, and have been in use for many years. Much effort has gone into the development of such gauges that can be efficiently and economically manufactured and that are aesthetically pleasing. Numerous patents have been issued on various designs and constructions for such gauges, such as U.S. Pat. Nos. 4,163,428; 4,215,647; 4,218,726; 4,274,358; 4,771,368; 5,839,811; 5,915,822; 5,934,782 and 6,276,809;.
It is one object of the present invention to provide an improved design for a gauge having an illuminated dial and pointer, that can be efficiently manufactured at a relatively low cost because of the simplicity of the construction, and yet still provides good illumination of the dial and pointer and is aesthetically pleasing. In this connection, a one specific object of this invention is to provide such an improved gauge that does not require a separate light source for the pointer.
It is a further object of the present invention to provide such an improved gauge that has relatively few parts and can be made small, compact and lightweight.
Another object of the invention is to provide such an improved gauge that illuminates the pointer uniformly regardless of the angular position of the pointer.
A still further object of the present invention to provide such an improved gauge which generates very little heat.
In accordance with the invention, there is therefore provided a gauge comprising a light-transmitting dial plate having a front surface with indicia for a variable represented by the dial, at least one light source spaced rearwardly from the rear surface of the dial plate for illuminating the dial plate, and a light-transmitting pointer mounted for rotational movement about an axis normal to the dial plate. The pointer has a hub concentric with the axis, extending through the dial plate and projecting both forwardly and rearwardly from the plate, and an indicator projecting laterally from the hub across a portion of the front surface of the dial plate. The portion of the hub extending rearwardly of the dial plate is shaped to capture light directly from the light source so that light enters the hub and propagates forwardly through the hub, and then laterally from the hub into the indicator to illuminate the indicator.